BRUSSELS (AFP) - Luxembourg investment firm Genii Capital -- which was backing Formula One boss Bernie Ecclestone's bid to buy Saab from General Motors -- on Monday said it was dropping out of the race.

"Genii Capital concluded today that the timing of the bidding process for Saab is incompatible with implementing a solid business platform for the future," it said in a statement.

The firm said it had engaged in "a period of intensive study and evaluation," having been "brought into the year-long bidding process for Saab just three days before the closing deadline."

However, it concluded that the "next stage" in an existing partial shutdown at Saab introduced during the negotiations was not compatible with "closing the transaction."

The decision leaves Dutch sportscar maker Spyker as the only bidder for GM's loss-making Swedish unit.

Saab, which employs 3,400 people in Sweden, is one of four brands being shed by GM as part of a massive restructuring effort that began in 2005 and accelerated last year when the largest US automaker went bankrupt.

Analysts have warned that some 8,000 jobs could be lost with Saab's closure.